Do you exhaust the reflector or blow air through it?It depends on how much air you want to move and how quiet you want it. All the way from $29 Lowes inline fans, which are noisy to vortex and some of the other fans which you can spen $300 on.
Try it both ways and see. The routing of the ducts can change the results.Do you exhaust the reflector or blow air through it?